<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		我是b页面<br />
		<input type="button" value="后退" onclick="goBack()">
	</body>
	<script>
		function goBack(){
			//history对象的go(-1)
			window.history.go(-1);
		}
	</script>
</html>
